1. Field
The presently disclosed subject matter relates to a vehicle lighting device.
2. Description of Related Art
In a conventional projector-type vehicle lighting device, the upper rim of a shade is arranged near the focus of a projector lens, a bulb is arranged near the first focus of an ellipsoidal reflector, and the second focus of the ellipsoidal reflector is arranged near the focus of the projector lens (see, for example, Japanese Patent Application Laid-Open No. 2003-331617). The light emitted from the bulb is reflected in the front direction by the ellipsoidal reflector, and a part of this reflected light is blocked by the shade while the rest of the reflected light which is not blocked is emitted in the front direction through the projector lens. The light emitted through the projector lens does not illuminate above the horizontal plane passing through the optical axis of the lighting device, but illuminates below this horizontal plane. Thereby, a light distribution pattern for going by oncoming vehicles is formed, so that it is possible to prevent occurrence of glare with respect to oncoming vehicles.
The projector-type vehicle lighting device has a switching lighting device which enables switching between a high beam for driving and a low beam for going by oncoming vehicles, by falling or standing the shade. When the shade is standing, since the upper rim of the shade is positioned near the focus of the projector lens, a part of the light reflected by the ellipsoidal reflector is blocked by the shade. Therefore, a low beam for going by oncoming vehicles is formed. When the shade falls, since the upper rim of the shade is away from the focus of the projector lens and the second focus of the ellipsoidal reflector, the light reflected by the ellipsoidal reflector is not blocked by the shade. Thereby, a high beam for driving is formed.
Incidentally, in a conventional high beam/low beam switching lighting device, downward light which is not blocked in a low beam mode becomes downward light in a high beam mode. On the other hand, upward light which is blocked in the low beam mode stops being blocked in the high beam mode, and becomes upward light in the high beam mode. Hence, even when the high beam/low beam switching is performed, there is only a slight change in brightness of downward light and there is only a slight visual difference between the high beam and the low beam.